Added Tooltip component to Button with tooltip prop

• Added:
- Tooltip component to Button with tooltip prop

app/javascript/gabsocial/components/tooltip.js

@@ -0,0 +1,38 @@
+import React from 'react'
+import PropTypes from 'prop-types'
+import { Popper } from 'react-popper'
+import Text from './text'
+
+class Tooltip extends React.PureComponent {
+
+  render() {
+    const { message, targetRef } = this.props
+
+    return (
+      <Popper
+        placement='top'
+        referenceElement={targetRef}
+        strategy="fixed"
+      >
+        {({ ref, style, placement, arrowProps }) => (
+          <div ref={ref} style={style} data-placement={placement} className={[_s.z4, _s.mt5, _s.mb5, _s.px5, _s.py5].join(' ')}>
+            <div ref={arrowProps.ref} style={arrowProps.style} />
+            <div data-popover='true' className={[_s, _s.bgBlackOpaque, _s.px10, _s.py5, _s.circle].join(' ')}>
+              <Text color='white' size='small' className={_s.minW120PX}>
+                {message}
+              </Text>
+            </div>
+          </div>
+        )}
+      </Popper>
+    )
+  }
+
+}
+
+Tooltip.propTypes = {
+  message: PropTypes.string.isRequired,
+  targetRef: PropTypes.node.isRequired,
+}
+
+export default Tooltip